With hurricanes, meterologists look at the wind speed and classify them at the time based on this. They start out low and then can go up to CAT 5 based on wind speeds. Why don't we do the same type of scale for tornados? Can the radar we have now see how fast the winds are going and then say this tornado has been known to be a category whatever tornado? If you have a mile wide tornado with 200+ MPH winds but it only hits a string of fields and just knocks down telephone poles with no damage more than that is it still just an EF1?

Tornadoes are so small, isolated and short-lived compared to a hurricane that it would be impossible to do this. Additionally the radar beam from the National Weather Service's can't see what's going on at ground level, the further away from the radar site the higher up the beam of the radar is.

To do this they would need a radar right next to the tornado scanning the tornado's wind velocity at ground level, not practical when dealing with such isolated and small-scale event that develops in a matter of seconds.

Hurricanes are really big. Tornadoes are fairly small.

As JoeyK already said, the lifespan of a tornado isn't long enough to collect as much data as from a hurricane. In addition, hurricanes have "eyes", areas in the middle that are fairly serene. And the eye of a hurricane is large enough to fly a large airplane into! And they do fly airplanes into hurricanes (and not just the eye).

I'm guessing, but I believe that the thing that makes a tornado far more destructive per square mile is the angle of the wind. Tornadoes spin in tight circles, while hurricanes are so large that their circular winds behave much more like straight line winds.

Fixed land-based radars measure winds at altitude, but can't measure wind speeds on the ground --where the damage is being done. The DOW radar vans are attempting to measure the winds at lower elevations, hoping to shed light on this unknown. Current Doppler weather radar installations that are operated by NOAA can't see the wind vectors on the ground, and therefore can't predict the strength of a tornado accurately.

Remember from the movie "Twister" the Fujita Scale is based on what the Tornado destroys or "eats" based on dollar value, damage done and lives lost. A Mile Wide Tornado in open country just tearing up grass land is basically an F0 or F1, maybe an F2 if a fenceline is taken out, a windmill nocked down and a few cows killed. Then look at the Jarrel, TX tornado from 1997, an F5 Finger of God meat grinder that leveled houses and wiped familes from the face of the Earth, leaving gouges in the concrete slabs of the houses it destroyed, it sat over that spot with little or no ground speed or movement for almost 10 minutes and was only about a quarter mile wide at that point of the storm. That tornado morphed more in size and strength than any previous storm on record. It also had traveled over 70 miles on the ground and across two lakes before hitting Jarrel. No instruments availalbe then or now would survive a tornado like that one.

On the other hand, Hurricanes are huge and last for a really long time. The US Air Force and Navy in conjuction with the US Dept. of Transportation send hurricane hunter aircraft to FLY INTO THE STORM to get measurements on the winds and barrometric pressure readings by dropping sounder buoys into the storm. Those planes are purpose built for that mission. But a huricane is a large scale mesocyclone and the energy is spread out over the entire storm. A tornado is also a mesocyclone, the scale is so much smaller, the energy is concentrated and flying into a tornado would be a disaster.

The EF or Enhanced Fujita Scale uses the wind speed velocities measured by the Doppler Radar, but as Josh explains on the show, only probes near or in the direct path of the tornado can measure those winds and pressure changes near ground level.